# Find all numbers which are equal to the sum of the factorial of their digits

December 22, 2011Hope you have enjoyed http://www.askqtp.com/2011/12/factorial-how-i-coded-it.html

Now let me find out some number in such a way that sum of factorial of each digit of that number is equal to that number.

like-145 is a curious number, as 1! + 4! + 5! = 1 + 24 + 120 = 145

So the logic is --

1.Get the number

2. Find out each digit of that number

3. Find out factorial of that number

4. Sum of the factorials

5. Check if the original input is equal to the sum

6. if they matches print the result.

How to code:

## 1. get user input..

Please go throughhttp://www.askqtp.com/2011/12/how-to-take-user-input-in-java-how-i.html

## 2. Now I need to create a logic that will give me the digits from a number.

private void getDigit(int number)

{

int tmp = 1;

while(number > 0)

{

tmp = number % 10;

number /= 10;

System.out.println(tmp );

}

}

{

int tmp = 1;

while(number > 0)

{

tmp = number % 10;

number /= 10;

System.out.println(tmp );

}

}

## 3.Find out factorial of that number

for this again refer to http://www.askqtp.com/2011/12/factorial-how-i-coded-it.html.

## 4. Sum of the factorials

so after getting factorials for each digit we need to sum these.let me write a function for it which will call factorial method and sum them up.
private int addfactOfDigits(int number) {

long result = 0;

int tmp = 1;

while(number > 0) {

tmp = number % 10;

//recursive factorial method more details on here

result += recfact_withoutstatic(tmp);

number /= 10;

}

return (int)result;

}

}

long result = 0;

int tmp = 1;

while(number > 0) {

tmp = number % 10;

//recursive factorial method more details on here

result += recfact_withoutstatic(tmp);

number /= 10;

}

return (int)result;

}

}

## 5. Check if the original input is equal to the sum

if (i== addfactOfDigits (i))

//i is the number we are passing to our function addfactOfDigits

System.out.println(i);

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